Slow order control for railway locomotives



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United States Patent 3,218,455 SLOW ORDER CONTROL FOR RAILWAY LOCOMOTIVES J Donald Hughson, Rochester, N.Y., assignor to General Signal Corporation Filed Nov. 21, 1960, Ser. No. 70,477 4 Claims. (Cl. 246-187) The present invention relates to the automatic control of a vehicle, and more particularly to the automatic control of a locomotive along a railway track. Specifically, the present invention relates to apparatus for changing the throttle and braking control of a locomotive in accordance with irregular portions existing along a length of track over which the locomotive is to travel, such as a downgrade, or a curve, for example.

At the present time, it is proposed that the operation of unmanned railway locomotives be automatically controlled over a railroad track in accordance with the traffic conditions ahead of the locomotive. This is accomplished by means of continuous coded track circuit information which is received by the locomotive through suitable receiving coils located thereon; the operation and speed of the locomotive being governed in accordance with the presence or absence and rate of this coded track circuit information.

However, in a track layout, because of the terrain on which the track is situated, there are sections which present a downgrade or a curve. When an automatically controlled locomotive is traveling over a stretch of track which is downgrade, it will gradually increase its speed depending on the angle of the grade until it is traveling at an unsafe speed. Also, when a train reaches a curve in the track, its trafiic controlled speed may be excessive for negotiating the curve with the result that a derailment is likely to occur.

Therefore, in order to provide for the safe operation of automatically controlled unmanned locomotives, it is necessary that the locomotive be further controlled in accordance with the terrain on which the track is situated, and this control must also permit the proper operation of the locomotive over such downgrade or curve in accordance with the trafi'ic conditions ahead of the train.

One of the objects of the present invention is to provide for controlling the speed of an automatically controlled vehicle in accordance with the terrain on which the track is situated.

Another object of this invention is to provide for controlling a locomotive at a safe speed over downgrades and/or curves, regardless of the permissive speed governed by trafiic conditions ahead of the train.

A still further object of this invention is to provide apparatus of the character described which can be selectively controlled according to the angle of the grade, and/ or the radius of curvature of the track.

Other objects of this invention will become apparent from the specification, the drawings, and the appended claims. In the drawings:

FIGS. 1A, 1B, 1C and 1D when arranged according to FIG. 2 illustrates schematically a typical track layout, wayside apparatus, and locomotive carried apparatus according to one embodiment of this invention;

FIG. 2 illustrates the arrangement of FIGS. 1A, 1B, 1C and 1D; and

FIG. 3 is a schematic circuit arrangement for controlling the throttle and brakes according to this embodiment of the invention.

The present invention is adapted to be used with a system that controls the speed of a train according to the trafiic conditions ahead of the train, wherein the rate of 3,218,455 Patented Nov. 16, 1965 a continuously coded track circuit, for example, automatically operates the train at a slow, medium, or fast speed; wherein an overspeed control apparatus is provided to slow the train in the event it is above the permissive speed limit, and wherein the apparatus is so connected to be fail safe. The general organization of such a train carried system, for automatically operating unmanned locomotives, is disclosed in my copending application Ser. No. 74,901 filed December 9, 1960. The common subject matter of this application and the above copending application, for operating locomotives, is claimed only in my copending application Ser. No. 74,901.

In accordance with the present invention a length of railway track is provided with conventional continuous coded track circuit apparatus 10 to continuously energize the track with a rate of either 75, 120, or 180 depending on the traffic condition on the track ahead of the train. When the track is energized with a rate of 75, traffic conditions are such that the train is required to proceed at a speed not in excess of seven miles per hour. When the track is energized with a rate of 120, traffic conditions are such thaat the train is required to travel at a speed not in excess of fifteen miles per hour. Also, when the track is receiving a code rate of 180, tratfic conditions permit the train to be operated at full speed or approximately thirty miles per hour, for example. For convenience of description, the track layout illustrated in FIGS. 1A and 1B is shown as one track section wherein a particular track circuit code is impressed on the rails throughout its entire length.

A locomotive L is equipped with receiving coils RC2 and RC3 (FIG. 1A) at the front thereof in proximity to the track rails. These coils RC2 and RC3 are connected through a transformer 12, and through filter and amplifier clipper circuits to the primary winding of a saturable transformer 14. A code following relay CR is connected to the output of secondary winding 16. Decoding units DU, DU, and DU (FIG. 1C) serve to decode the frequency of operation of the coding relay CR in accordance with the rate of the energy flowing through the track to energize decoding relays 75R, 120R or 180R respectively.

The overspeed control apparatus located on the locomotive is illustrated in FIGS. 1A and 1B, and includes a frequency generator FG, the output of which is normally selectively directed to different high pass filters 20, 22, 24 and 26 in accordance with the code frequency received by the train. High-pass filter 20 block energy applied thereto when the locomotive is travelling at less than five miles per hour. High-pass filter 22 blocks energy applied thereto when the train is travelling at less than eleven miles per hour. Similarly high-pass filters 24 and 26 serve to block energy applied thereto when the train is travelling at less than twenty-one and thirtysix miles per hour respectively. A C relay is provided to be energized when a respectively selected filter 20, 22, 24 or 26 permits energy applied thereto to be blocked by the filter. Thus, the C relay which is an over-speed relay, is provided to be energized when the train is travelling below five miles per hour and energy is applied to the filter 20; when the train is travelling below eleven miles per hour and energy is applied to the filter 22; when the train is travelling below twenty-one miles per hour and energy is applied to filter 24; and is energized when the train is travelling below thirty-six miles per hour and energy is applied to filter 26.

Relays D and DP are provided for registering an overspeed condition, and the relay C is provided to control the locomotive motor in accordance with such overspeed condition. Relays VD and VDP are provided to detect any failure on the part of the frequency generator and are energized when the train is travelling over two miles per hour.

In accordance with the present invention, grade information tuned coils G1, and G2 are provided to be disposed along the wayside adjacent the track to transmit grade information to the locomotive. In the illustrated embodiment of the invention coil G1, which may the tun'ed'tot210kilocycles, for example, is provided to detect a slight grade. Coil G2, which may be tuned to 250 kilocycles, for example, is provided to detect a medium grade. For providing information as to a steep grade, coils G1 and G2 may be positioned close to one another to exercise a different control over the train. Tuned coil 60 is provided to cancel the grade information when the train again reaches track which is fairly level. This coil may be tuned for 170 kilocycles for example. For continuous grades of varying degrees coils G1 and G2 may be placed at any desired position and the coil GC placed at the end thereof. In FIG. 1A, the .tuned coil G1 is illustrated by way of example, as being at the beginning of a slight grade and the coil GC is at the end of this grade. Coil G2 is shown at the start of a steeper grade and the coil GC is at the end thereof.

That portion of the track layout illustrated in FIG. 1A represents two curved portions of track. A tuned coil S1 is provided to be positioned adjacent the track at the approach of a slight curve and orders the train to slow down to miles per hour. This coil may be tuned to a frequency of 290 kilocycles. A tuned coil S2, which may be tuned to 130 kilocycles, for example, is provided to be disposed at the approach to a sharper curve for slowing the train down to 7 miles per hour. Tuned coils SC, which may be tuned to 375 kilocycles are provided to be disposed at the ends of the respective curves for cancelling the slow order provided at the approach to the curves.

A pick-up coil PU is provided on the locomotive L to receive the impulses of the tuned coils G1, G2, GC, GC S1, S2, and SC. A sweep oscillator 28 which i distinctly affected by the frequency detected by the coil PU selectively passes. energy through associated band-pass filters 30, 32, 34, 36, 38, and 40,respectively. Connected to each of these band-pass filters is a relay GCR, GlR, G2R, SIR, 82R, and SCR respectively. These relays are energized whenever its associated filter is activated in accordance with the frequency of the sweep oscillator 28,

as governed by the passage of the locomotive past a corresponding one of the grade coils G1, G2 or GC, or a corresponding one of the slow order coils S1, S2, or SC.

A relay EMR is provided to be constantly energized when the track is receiving a code rate of thirty-seven or above. This relay will become deenergized when a lesser code rate or no code rate is received through the track rails.

Relays GR1 and GR2 are provided to retain the grade information which is supplied by the relay G1R and G2R, and this information is cancelled by the relay GCR. Relays S07 and S015 are provided to retain the slow order information which is supplied by the relays 51R and 52R. This information is cancelled by the relay SCR.

Relays P7, P15 and P30 are so connected to be energized when the locomotive is controlled to proceed at seven miles per hour, fifteen miles per hour, or thirty miles per hour, respectively. The relay ST is provided to be energized when the train is to make a normal top. The stop relay ST when picked up deenergizes a conventional electropneu-matic valve relay EPVR (not shown) to apply the brakes of the train. These relays are governed in accordance with the track code rate received on the train and the grade and slow order information when applicable.

The output of the frequency generator FG is also connected through an amplifier 39 to a plurality of highpass filters H (FIG. 1D) which are selectively energized in accordance with the speed of the train. High-pass filter H5, for example, provides an output when the frequency generator FG detects that the train is travelling at any speed above five miles per hour. Filter H7 provides an output when the train is travelling above seven miles per hour, and the remainder of the filters H provide an output when the train is travelling at a mile per hour rate above the value of the numerical sufiix of each respective filter H. The output of each high-pass filter H energizes its associated relay SP.

Locomotive throttle and braking control apparatus is illustrated in block diagram in FIG. 1D, and the circuitry for operating this apparatus is schematically shown in FIG. 3. Wire 41 (FIG. 3) when deenergized, causes a conventional electropneumatic valve relay EPVR (not shown) to be deenergized to apply the brakes of the train. Wires 42 are energized when the throttle control is to cause the locomotive engine to idle. Wires 44, 46 and 48 are energized when the throttle is to be controlled to high, medium, and low, respectively.

A more detailed description of the system according to the illustrated embodiment of the invention will be given in connection with a description of its operation under examples of typical operating conditions.

Assuming that the railroad tracks are receiving a code rate of 180, which indicates that a locomotive travelling thereon is normally controlled at the maximum permissive speed, such as thirty miles per hour, for example, the coding relay CR is intermittently energized at a frequency of 180 rate- In response to the operation of the relay CR at this frequency, the decoding unit 180DU (FIG. 1C) causes the relay 180R to be energized. The energizing of the relay 180R through the decoding unit 180DU is caused by the intermittent opening and closing of contact 49 of the relay CR. Also, the operation of contact 50 of the relay CR energizes the slow drop away relay CRFP and the slow drop away relay 37R. During the pulsing of the contact 50 of the relay CR, the slow drop away characteristics of the relay 37R maintain the emergency relay EMR steadily energized by front contact 51 of the relay 37R.

The picking up of the relay 180R energizes the proceed relay P30 by a circuit which extends from and includes front contact 52 of the relay EMR, back contact 53 of the relay R, back contact 54 of the relay R, front contact 55 of the relay R, front contact 56 of the relay VD, back contact 57 of the relay S07, back contact 58 of the relay S015, wire 60, the winding of relay P30, wire 61, back contact 62 of relay S015, back contact 63 of relay S07, front contact 64 of relay VDP, front contact 65 of the relay 180R, back contact 66 of the relay 120R, and back contact 68 of the relay 75R to The relays VD and VDP are checking relays and have front contacts in the respective pick-up circuits for the relays P7, P15, and P30 and the overspeed control selection circuits to insure that the frequency generator FG is operating properly.

The picking up of the relay 180R also connects the highpass filter 26 to the output of the frequency generator PG. The circuit for connecting the filter 26 to the output of the generator FG extends from output amplifier- 120R, back contact 84 of relay 75R, amplifier 85 and the winding of the relay D to a positive terminal of a suitable source of energy.

Assuming that the locomotive is travelling at a speed less than the maximum speed permitted for the received code rate of 180, the output of the frequency generator FG is blocked by the high-pass filter 26 through the previously mentioned circuit. A check frequency generated by oscillator 86 (FIG. 1A) is applied, however, to the amplifier 70 of a frequency to be passed by the filter 26. This check frequency causes the relay D to be energized through the amplifier 85. This picking up of the relay D energizes the repeater relay DP. The picking up of the relay DP renders the oscillator 86 ineffective, by the opening of back contact 88 and subsequently relays D and DP are successively dropped away. This establishes a checking organization wherein the relays D and DP are pulses continuously as long as the speed of the locomotive is below a predetermined speed which is determined by the circuit which connects the particular highpass filter 20, 22, 24 and 26 to the output of the generator FG. In this example, the filter 26 has been selected because the relay 180R is energized. The previously described pulsing of the relay DP is then effective to energize the relay C (FIG. 1A) because of alternately charging the capacitor 91 through front contacts 92 and 93 of the relay DP, and discharging the capacitor 91 through the winding of relay C and a resistor 94. The winding of relay C is shunted by capacitor 05 to maintain the relay C picked up during the charging of the capacitor 91.

When the frequency of the generator F6 is such to indicate that the train has exceeded in this example, 36 miles per hour, the filter 26 provides an output which holds the front contact 87 of relay D picked up which holds the relay DP energized, and consequently causes the deenergizing of the relay C.

With the relay C energized which indicates that the train is travelling below thirty-six miles per hour, and the train is actually travelling below 28 miles per hour, the high throttle control (FIG. 1D) is energized by a circuit which extends from and includes front contact 100 of relay P30, wire 101 (FIG. 3), front contact 102 of relay C, front contact 103 of relay EPVR, back contact 104 of relay 3251, back contact 105 of relay 30SP, back contact 106 of relay 28SP and wire 48 to the high throttle. When the train increases its speed to 28 miles per hour, front contact 106 of relay 28SP closes which changes the energy applied to the high throttle wire 48 to the medium throttle wire 46 through the front contact 106 of the relay 28SP, back contact 107 of the relay GRZ, and back contact 108 of the relay GRl. When the speed of the train increases to 30 miles per hour, the front contact 105 of relay 30SP closes, thereby deenergizing the medium throttle wire 46 and energy is applied to the low throttle wire 44 through front contact 105 of relay 30SP, back contact 110 of relay GRl, and back contact 111 of relay GR2. If the train should thereafter increase its speed to 32 miles per hour, contact 104 of relay 32SP shifts to apply energy to the idle throttle wire 42 by a circuit which includes front contact 104 of relay 32SP. If the speed should further increase to above 36 miles per hour, the relay C would be deenergized as previously described. This deenergizing of relay C removes energy from the normally energized wire 41 to the braking relay EPVR (FIG. 3) by the opening of front contact 114 of relay C, thus applying the brakes of the train. The idle throttle wire 42 is then energized by the closing of the back contact 102 of the relay C, which keeps the engine at idle so that it will not shut off. Thus, in this embodiment of the invention, if the train should exceed thirty-six miles per hour positive braking will be applied under normal conditions when the track code is at a 180 code rate.

It follows from the circuitry in FIG. 1B that if the track is receiving a code rate of 120, the output of the frequency generator FG will be applied to the high-pass filter 24 which would cause the brakes to be applied when the train exceeds 21 miles per hour. In this event the relay 120R would be energized together with the relay P15. It is apparent therefore that the EPVR wire would be deenergized to cause a brake application when front contact 115 of relay C opens (FIG. 3). Similarly, if a code rate of 75 is applied to the track the output of the frequency generator FG is applied to the filter 22 and when the train exceeds 11 miles per hour front contact 116 of relay C opens to apply the brakes of the train. As

viewed in FIG. 3 the various speed relays for appropriate train speeds are included in the circuits for energizing the low and medium throttle wires so that the train will receive proper control under all traffic conditions.

When a code rate of less than 75 but more than 37 is applied to the track rails the locomotive motor is throttle held to an idle condition by a circuit (FIG. 1C) which extends from and includes back contact 129 of relay 75R, back contact 117 of relay R, back contact 118 of relay 180R, wire 119, back contact 120 of relay P30, back contact 121 of relay P15, back contact 122 of relay P7, front contact 123 of relay ST, and idle wire 124 to the motor control apparatus. The relay ST is energized under these conditions by obvious circuitry which includes back contact 53 and 68 of the relay 75R, back contacts 54 and 66 of relay 120R, and back contacts 55 and 65 of relay 180R. This situation prevails when a train is required to make a normal service stop. The brakes would be applied to the train under these conditions by removal of energy from wires 101, 99, 153, thus deenergizing the EPVR wire.

In the event the frequency generator FG should fail mechanically, the relays VD and VDP would become and remain deenergized to restrict the speed to eleven miles per hour for example. Other restrictive speeds could be selected.

Assuming, according to this example that the train is receiving a code rate of 180, the locomotive L is travelling at 30 miles per hour on a level track and the locomotive comes to a slight down-grade wherein a tuned coil G1 is placed along side of the tracks, the pick up coil PU is activated in accordance with a certain frequency to energize the relay G1R through its band-pass filter 32. The energizing of the relay GlR energizes the relay GRl by a circuit which extends from and includes front contact 126 of relay 61R and the winding of relay GR1 to The relay GR1 is held energized by a stick circuit which extends from and includes back contact 127 of relay GCR, front contact 128 of relay GRl and the winding of relay GR1 to Upon the picking up of the relay GR1, energy is removed from the low speed throttle wire 44, of FIG. 3 by the opening of the back contact 110 of relay GRl and the idle throttle wire 42 is energized by the closing of the front contact 110 of the relay GRl. This throttles down the motor of the locomotive upon receiving information that it is approaching a slight down-grade. When the locomotive increases its speed to 32 miles per hour because of so much grade, the relay 32SP will be energized thus deenergizing the braking relay EPVR (not shown) to apply the brakes of the train because back contact 130 of relay GRl is open. Thus, the throttle control is decreased and the brakes applied before the train has an opportunity to reach a dangerous speed wherein the brakes would be applied by the dropping away of the relay C as hereinbefore described. It is apparent that if the train were travelling below 30 but above 28 miles per hour when it approached the grade and the relay 28SP is energized as a result thereof, front contact 108 of the relay GRl would close which would change the throttle setting from medium to low by changing the output of energy to the wire 44. Thus, the tuned coil G1 anticipates a certain increase in speed and difiiculty of slowing the locomotive because of a distinct grade and the apparatus on the locomotive causes a change in the throttle setting when the locomotive passes the coil, in accordance with the actual speed of the locomotive.

At the end of the grade when the track again levels off, the coil PU is influenced by the tuned coil GC which is disposed along side the track. This activates the bandpass filter 30 to energize the relay GCR momentarily 7. thereby interrupting the previously described stick circuit for the relay GR1 to cancel the grade information. The dropping away of the relay GRI restores the motor control circuits to normal so that the train again is controlled by traffic conditions only.

In the event that the locomotive L approaches a steeper grade and its coil PU is influenced by the tuned coil G2, the relay G2R is energized, which picks up the relay GR2 by an obvious circuit. Upon the picking up of the relay GR2 when the train is travelling below thirty but above twenty-eight miles per hour, the throttle control is immediately transferred from medium to idle by the closing of front contact 107 of relay GR2 when the relay GRI is deenergized. It is apparent that the relay GR2 provides a more severe decrease in throttle control than the relay GRl. For a still more severe grade tuned coils G1 and G2 may be placed in close proximity so that both the relays GR1 and GR2 will become energized thus placing a still more restrictive control on the locomotive. The coils G1 and G2 may be placed at the beginning of adjoining grades without intervening cancel coils GC to cause the decrease of throttle control to be applicable in accordance with any specific downgrade encountered.

Assuming that the locomotive L is travelling on a level track at a maximum permissible speed of thirty miles per hour, and it approaches a slight curve that has a slow order coil S1 at the approach thereto, the relay 81R is energized by the activation of its band-pass filter 36 to energize a slow order relay S015. The circuit for energizing the relay S015 extends from and includes front contact 132 of relay SIR, and the winding of relay S015 to The relay S015 is held energized by a stick circuit which includes back contact 134 of relay SCR, front contact 136 of relay S015 and the winding of relay S015 to Upon the picking up of the relay SO the maximum over-speed control is changed to drop away the relay C when the .train exceeds 21 miles per hour instead of 36 because of the closing of front contacts 77 and 79 of the relay S015. Also, the relay P is deenergized by the opening of back contacts 58 and 62 of relay S015. The closing of the front contacts 58 and 62 of the relay S015 energizes the relay P15 which transfers the motor control apparatus to the medium throttle control. The circuit for shifting the throttle control extends from and includes back contact 97 of relay P30, front contact 98 of relay P15, and wire 99. Thus as illustrated in FIG. 3, the throttle is controlled through the contacts 115 and 140 of the relay C. If the locomotive should be travelling in excess of 21 miles per hour the relay C is deenergized as previously described to apply the brakes of the train by the opening of front contact 115 of the relay C. When the locomotive decreases its speed to twenty-one miles per hour, the relay C is again energized which releases the brakes, and the idle wire 42 is energized through front contact 140 of relay C and front contact 141 of the relay 178?. When the locomotive decreases to below seventeen miles per hour, the relay 17SP will drop away and the low speed throttle wire 44 will be energized through front contact 142 of relay 15SP. If the train should decrease its speed below fifteen miles per hour, back contact 142 of the relay 15SP would close thus causing the throttle setting to advance to the medium throttle wire 46 through front contact 143 of the relay 13SP. In the event the train should still further decrease its speed below the maximum called for by the slow order coil S1 to thirteen miles per hour, or below, back contact 143 of the relay 13Sl would close thereby applying energy to the high throttle Wire 48 to bring the train back up to speed.

At the end of the curve a slow order cancel coil SC is placed along side the track which causes the relay SCR to be energized because of the influence of the pick up coil PU which opens back contact 134 of the relay SCR to deenergize the relay S015. The dropping away of the relay S015 again energizes relay P30 in accordance with the 180 code rate of the track and connects the output of the frequency generator back to the high-pass filter 26. The locomotive will now increase its speed to the maximum permitted in accordance with traffic conditions.

Assuming that the locomotive encounters a more pronounced curve which is anticipated by the placing of a tuned coil S2 at the approach to the curve, the pick-up coil PU causes the band-pass filter 38 to be activated thereby energizing the relay 52R. The relay 52R energizes the relay S07 by a circuit which extends from and includes front contact of relay 52R and the winding of relay S07 to The relay S07 is held picked up by a stick circuit which extends from and includes back contact 151 of the relay SCR, front contact 152 of the relay S07 and the winding of relay S07 to Upon the picking up of the relay S07, the relay P30 is deenergized by the opening of back contacts 63 and 57 of the relay S07. The closing of the front contacts 63 and 57 of the relay S07 energizes the relay P7 which changes the main throttle control from the wire 101 of FIG. 1D to wire 153. The picking up of relay S07 also changes the output of the frequency generator PG from the high-pass filter 26 to the high-pass filter 22 by the shifting of contacts 76 and 80 of the relay S07. The locomotive is now controlled to travel at seven miles per hour. Assuming that the locomotive is travelling at thirty miles per hour, the over-speed control will cause the relay C to be deenergized thereby applying the brakes of the train until it decreases its speed to eleven miles per hour. When the relay C is again energized, because of the over-speed control, the brakes are again released by the closing of the front contact 116 of the relay C (FIG. 3) and the throttle control remains at idle by a circuit which extends from in FIG. 1D, and includes back contact 156 of relay P30, back contact 157 of relay P15, front contact 158 of relay P7, wire 153, front contact 160 of relay C, front contact 161 of relay EPVR, front contact 162 of relay 75F, and the control wire 42. When the train has been slowed down to below seven miles per hour. the contact 162 of the relay 7SP shifts to increase the throttle setting from idle to low by a circuit which includes back contact 162 of the relay 7SP, front contact 166 of the relay 5SP, back contact 167 of relay GR2 and the wire 44. If the locomotive should further decrease its speed below five miles per hour, the relay SSP drops away thus changing the throttle setting from low to medium by the energizing of the wire 46 through back contact 166 of the relay 5SP. Similarly, at the end of the curve a tuned coil SC is located which influences the pick up coil PU to open the stick circuit of the relay S07 by energizing the relay SCR.

"This causes the relay P7 to drop away and the relay P30 to be again energized in accordance with the code rate of the track circuit as previously described.

It is evident, that the grade information coils G could be used in conjunction with the slow order coils S so that the throttle changes of the locomotive could be further decreased more rapidly, than would ordinarily be the situation, in anticipation of more severe restrictions. Also, it is understood that although low, medium and high speed throttle controls are illustrated in this embodiment of the invention that other controls may be substituted therefore. Also, it is understood that other critical speeds required for the desired running control of the locomotive and its over-speed control may be substituted in accordance with the individual requirements of practice.

Having thus described one embodiment of apparatus for providing grade information and slow orders to an automatically controlled locomotive, it is to be understood that various adaptations, modifications and alterations may be made to this specific form shown to meet the requirements of practice without in any manner departing from the pirit or scope of this invention.

What I claim is:

1. In a system for governing the operation of a locomotive over a length of track in accordance with traflic conditions on the track ahead of the locomotive, said track having a straight and level portion and an irregular portion, locomotive motor throttle operating means for operating the throttle to a plurality of settings, speed registering means effective to register the actual speed of the locomotive, speed selection means effective to select the limit of speed of the locomotive in accordance with trafiic conditions, a first plurality of circuit means including said speed registering means effective to control the throttle operating means to operate said throttle to a selected setting as governed by a respective speed selection means and the actual speed the locomotive is travelling, a second circuit means including said speed selection means efiective to select one of said first plurality of circuit means to control the speed of the locomotive in agreement with a predetermined limit, information means at the approach to said irregular portion, receiving means on the locomotive operated by said information means when the locomotive passes said approach, and electrical means operatively connected in said first plurality of circuit means and including said receiving means when operated to control said throttle operating means to operate the throttle of the locomotive to a predetermined setting as governed by said information means in accordance with the actual speed.

2. A system according to claim 1 wherein said electrical means is operative to select a predetermined one of said first plurality of circuit means for selecting a predetermined limit of speed.

3. In a system for governing the operation of a locomotive over a right of way having a straight and level portion and an intermediate irregular portion, operating means on the locomotive for operating said locomotive along said right of way, control means operative to control the locomotive operating means to a first distinctive condition solely in accordance with the advance traflic conditions while said locomotive is on said straight and level portion, registering means partly on the vehicle and partly on the wayside operative to register on the vehicle a required second distinctive condition of said vehicle operating means selected in accordance with both the degree of irregularity of said irregular portion and the advance traffic conditions, said control means including code communication apparatus partly on the wayside and partly on said locomotive for communicating coded command signals to the locomotive distinctive of its proper speed for the existing advance trafiic conditions, said registering means including tuned circuit means located on the Wayside in approach to said irregular portion and vehicle carried receiving means distinctively responsive to its passage at the location of said tuned circuit means, and means at the leaving end of said irregular portion of the right of way effective to cause said control means to control the vehicle operating means to said first condition in accordance with advance trafiic conditions.

4. The combination specified in claim 3 wherein the frequency of said tuned circuit means is indicative of the degree of irregularity of said irregular right of Way portion.

References Cited by the Examiner UNITED STATES PATENTS 1,734,602 11/1929 Shaver 246-182 X 1,816,628 7/1931 Williams et al 246-187 1,824,144 9/1931 Howe 246-182 1,861,488 6/1932 Allison et al 246-63 2,080,087 5/1937 Crago 246-63 2,098,401 11/1937 Prescott 246-63 X 2,160,894 6/1939 Nicholson 246-63 2,188,293 1/1940 Williams 246-29 2,194,371 3/1940 Wallace 246-63 2,235,112 3/1941 Pulaski 246-182 X 2,287,108 6/ 1942 Kemmerer 246-63 2,291,372 7/1942 Bushnell 246-63 2,493,755 1/1950 Ferrill 246-182 2,661,070 12/1953 Ferrill 246-182 2,803,743 8/1957 Ballerait 246-63 2,852,086 9/1958 Cordry 246-182 3,072,785 1/1963 Hailes 246-187 X 3,140,068 7/1964 Matthews 246-167 FOREIGN PATENTS 806,625 12/1958 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

JAMES S. SHANK, EUGENE G. BOTZ, Examiners. 

1. IN A SYSTEM FOR GOVERNING THE OPERATION OF A LOCOMOTIVE OVER A LENGTH OF TRACK IN ACCORDANCE WITH TRAFFIC CONDITIONS ON THE TRACK AHEAD OF THE LOCOMOTIVE, SAID TRACK HAVING A STRAIGHT AND LEVEL PORTION AND AN IRREGULAR PORTION, LOCOMOTIVE MOTOR THROTTLE OPERATING MEANS FOR OPERATING THE THROTTLE TO A PLURALITY OF SETTINGS, SPEED REGISTERING MEANS EFFECTIVE TO REGISTER THE ACTUAL SPEED OF THE LOCOMOTIVE, SPEED SELECTION MEANS EFFECTIVE TO SELECT THE LIMIT OF SPEED OF THE LOCOMOTIVE IN ACCORDANCE WITH TRAFFIC CONDITIONS, A FIRST PLURALITY OF CIRCUIT MEANS INCLUDING SAID SPEED REGISTERING MEANS EFFECTIVE TO CONTROL THE THROTTLE OPERATING MEANS TO OPERATE SAID THROTTLE TO A SELECTED SETTING AS GOVERNED BY A RESPECTIVE SPEED SELECTION MEANS AND THE ACTUAL SPEED THE LOCOMOTIVE IS TRAVELLING, A SECOND CIRCUIT MEANS INCLUDING SAID SPEED SELECTION MEANS EFFECTIVE TO SELECT ONE OF SAID FIRST PLURALITY OF CIRCUIT MEANS TO CONTROL THE SPEED OF THE LOCOMOTIVE IN AGREEMENT WITH A PREDETERMINED LIMIT, INFORMATION MEANS AT THE APPROACH TO SAID IRREGULAR PORTION, RECEIVING MEANS ON THE LOCOMOTIVE OPERATED BY SAID INFORMATION MEANS WHEN THE LOCOMOTIVE PASSES SAID APPROACH, AND ELECTRICAL MEANS OPERATIVELY CONNECTED IN SAID FIRST PLURALITY OF CIRCUIT MEANS AND INCLUDING SAID RECEIVING MEANS WHEN OPERATED TO CONTROL SAID THROTTLE OPERATING MEANS TO OPERATE THE THROTTLE OF THE LOCOMOTIVE TO A PREDETERMINED SETTING AS GOVERNED BY SAID INFORMATION MEANS IN ACCORDANCE WITH THE ACTUAL SPEED. 